Improvement in grate-bars for furnaces



A. RAWSON.

lmpvrovementin Grate-Bars for Furnaces.`

UNITED STATES ALONZO RAWSON, DES MOINES, IOWA.

IMPROVEMENT IN @RATE-BARS Fou FuRNAcEs.

. peciicaton forming part of Lettere Patent No. 129,862, dated July 23, 1872.

` SPECIFICATION.

Specification describing certain Improvements in Grate-Bars for Furnaces, invented o by ALONZO RAWsoN, of Des Moines, in the county of Polk and State of Iowa.

My invention is an improvement of my gratebar for furnaces patented June 4, 1872, No. 127,428. It consists in forming a grate-bar withan opening and a rim on the under side, in such a manner that when a series of the bars are placed together to form a grate an open passage is provided forthe reception of `an `air-distributing tube, as hereinafter fully set forth. i

Figure l of my drawing is a perspective 'view of the front end of a bar, and illustrates the manner of forming the opening and rim on the' under side. A A represent ya common bar. B is a half-round cavity extending across the under `half of the bar. The posi-` tion, size, and shape of this cavity may vary. O C is a half-circle rim cast solid with the bar. It conforms in shape and position with the cavityB to produce an opening for a blowpipe or air-distributing tube. This rim C C may be left off, and the tube ,D inserted and secured in the cavity B in any common way to lateral projections on the sides of the bars. A separate tube could be inserted in that chamber or passage in the manner and for the purpose contemplated by my improvement; but it would be a double tube and a double expense, that can be saved by the use of the invention herein described.

I am aware that air-distributing tubes and chambers have been attached under furnacegrates in various ways for the purpose of cooling the bars and blowing the fire. I claim, however, that my mode of forming a bar to produce a passage for a tube within the grate, as set forth, is new and greatly advantageous. The perforated tube D can be inserted or withdrawn whenever desired. The metal taken from the cavity B forms the ri'm C O. The

bar is not weakened and the cost is not in- Claims.

I claim as my invention- 1. The grate-bar A A with cavity B and rim C C, substantially as described, and for the purposes set forth.

2. The combination of the air-distributing i tube D D with a series of grate-bars, A A, in the manner described, for the purpose of keeping the bars cool and to blow the fire.

ALONZO RAWSON. Witnesses:

L. A. GRAIN, HARRY 0. LUCY. 

